Waterproof breathable boot

ABSTRACT

A waterproof breathable boot comprises a sole, at least two panels forming an external shell having an outer most surface waterproof, an internal layer separate from the outer shell and connected to the external shell by the sole such that a gap of air is formed between the internal layer and the external shell, and a drying insert connected to the internal layer. The at least two panels are waterproofly bonded to each other. An adhesive is in direct contact with a first portion of the inner surface and a second portion of the outer surface waterproofly for bonding the first portion to the second portion. The internal layer has wicking properties and is protected from an outside of the boot by the external shell. A method of manufacturing a waterproof breathable boot is also presented.

TECHNICAL FIELD

The application relates generally to boots and, more particularly, towaterproof boots.

BACKGROUND OF THE ART

When working in humid environments, the boots have to fulfill twopurposes: prevents water to pass therethrough, and remove humiditygenerated by the foot. Two types of boots are currently available. Thefirst type is a leather boot. Leather boots are comfortable breathableboots with limited waterproof capabilities. Under repeated exposure towater the boot may become wet and may take a long time to dry. The bootmay then become heavier due to the water accumulated in the leather. Incold weathers, the wet leather boot can even freeze.

The other type of boots are rubber boots. While rubber boots areperfectly waterproof, they do little for the evacuation of humiditygenerated by the foot. When rubber boots are used, it may becomeuncomfortable for the user to walk for hours with wet feet.

Some have proposed a leather boot with a waterproof inner liner toremedy to the deficiency of the above two types of boots. However theleather being water permeable, water may accumulate between the leatherand the waterproof inner liner.

SUMMARY

In one aspect, there is provided a waterproof breathable bootcomprising: a sole; an external shell having an outer most waterproofsurface, the external shell extending to the sole and connectingthereto, the external shell including at least two panels, each panelhaving an outer surface and an inner surface, the outer surface of theat least two panels forming part of the outermost waterproof surface ofthe external shell, the outer surface and the inner surface of eachpanel being waterproof, the at least two panels being waterprooflybonded to each other, the waterproof bonding including an overlapping ofa first portion of the inner surface of one of the at least two panelswith a second portion of the outer surface of the other one of the atleast two panels, an internal layer separate from the external shell andconnected to the external shell by the sole such that a gap of air isformed between the internal layer and the external shell, the internallayer having wicking properties, the internal layer being protected froman outside of the boot by the external shell; and at least one dryinginsert, the internal layer carrying humidity from the wearer's foot tothe drying insert, the drying insert being exposed to the outside of theboot.

In another aspect, there is provided a method of manufacturing awaterproof breathable boot, the method comprising: cutting at least twopanels in a waterproof material having an outermost waterproof surface,the panels being cut in accordance to a pattern of the waterproofbreathable boot; positioning at least one of the two panels onto a footlast and sewing adjacent sides of the panels forming a back of the bootso as to create a back seam; waterproofly bonding a back strap onto theback seam, the back strap being made of waterproof material;waterproofly bonding a portion of an inside of at least one other panelto a portion of an outside of the at least one of the two panels so asto form a vamp of the boot until forming a waterproof external shell,respective outer surfaces of the panels forming an outer most waterproofsurface of the external shell; forming a wicking internal layer anddisposing it inside the external shell; and securing the internal layerand the external shell to a sole thereby connecting the internal layerand the external shell to each other.

In accordance with a further general aspect, there is provided awaterproof breathable boot comprising: a sole; an external shellextending upwardly from the sole, the external shell having an outermost waterproof surface, the external shell including at least twopanels having an outer surface and an inner surface, each panel having amultiply construction including at least one impermeable film laminatedon a microfiber substrate, the impermeable film being provided at saidouter surface of said at least two panels to form part of the outer mostwaterproof surface of the external shell, the at least two panels beingwaterproofly bonded to each other, the waterproof bonding including anoverlapping of a first portion of the inner surface of one of the atleast two panels with a second portion of the outer surface of the otherone of the at least two panels; and an internal layer mounted in theexternal shell with a gap of air therebetween, the internal layer havingwicking properties for carrying humidity away from the wearer's foot.

DESCRIPTION OF THE DRAWINGS

Reference is now made to the accompanying figures in which:

FIG. 1 is a side view of a waterproof breathable boot according to afirst embodiment;

FIG. 1 a is cross-section view taken along line 1 a-1 a in FIG. 1;

FIG. 2 is a schematic cross-section of a portion of an external shell ofthe boot shown in FIG. 1;

FIG. 3 is a schematic cross-section of a portion of the external shelland an internal layer of the boot shown in FIG. 1;

FIG. 4 is a waterproof breathable boot according to a second embodiment;

FIG. 5 is a waterproof breathable boot according to a third embodiment;

FIG. 6 is a waterproof breathable boot according to a fourth embodiment;and

FIG. 7 is a flow chart of a method of manufacturing the waterproofbreathable boot.

DETAILED DESCRIPTION

The following description will be made with reference to a boot. Itshould be understood that any other foot accessory, such as a shoe, orbootie could be used instead of a boot. The boot/shoe/bootie may be usedin a variety of environments including, none exclusively, street,mining, construction, backpacking, firefighting, hunting, military,leisure.

With reference to FIGS. 1 to 3, a waterproof breathable boot 10 will bedescribed. The boot 10 includes a waterproof external shell 14preventing fluid to permeate through the boot 10, and a wicking innerlayer 13 transporting humidity formed in a foot portion 10 a of the boot10 toward a calf portion 10 b of the boot 10 thereby rendering the boot10 breathable.

The boot 10 includes a sole 12 which may be made of rubber and may havea pattern depending on the use of the boot 10. For a boot 10 to be usedoutdoors, the sole 12 may have a pattern to increase adherence to theground. For street use, the sole 12 may have no pattern to beaesthetically pleasing.

The external shell 14 renders the boot 10 waterproof. The external shell14 defines an exterior 17 of the boot 10 and an interior 18 of the boot10. Thanks to the external shell 14 no fluid may communicate through theexternal shell 14 between the exterior 17 and the interior 18 of theboot 10, both ways. The external shell 14 may be directly connected tothe sole 12 by, for example, gluing edges of the external shell 14 tothe sole 12.

In the embodiment shown in the figures, the external shell 14 is made oftwo panels 14 a, 14 b. The external shell 14 could, however, be made ofmore than two panels. The panel 14 a forms a vamp of the boot 10, whilethe panel 14 b form a quarter of the boot 10. It is contemplated thatthe vamp of the boot 10 could not be unitary made, and be instead madeof two or more pieces. The boot 10 could also include a foxing.

Referring more specifically to FIG. 2, the panels 14 a, 14 b areindividually waterproof. An external surface 15 a, 15 b of the panels 14a, 14 b is waterproof and an internal surface 16 a, 16 b of the panels14 a, 14 b is also waterproof. The panels 14 a, 14 b may containnon-waterproof material between their external surfaces 15 a, 15 b andinternal surfaces 16 a, 16 b. This could be the case when, for example,the panels 14 a, 14 b are made of two or more layers of material bondedto each other. The panels 14 a, 14 b could also be made entirely ofwaterproof material. In any case, water, humidity and vapor may nottravel through the panels 14 a, 14 b both ways, as illustrated by arrows20 and 21.

In one embodiment, the panels 14 a, 14 b are each made of a unitarypiece of synthetic leather or polyurethane. However, it is understoodthat the panels 14 a, 14 b may be made of a waterproof material otherthan polyurethane.

According to another embodiment, each panel 14 a, 14 b is provided inthe form of a multiply material comprising first and second layeredstructures bounded together, such as by an adhesive (e.g. a glue). Eachlayered structure may comprise a layer of microfiber (e.g. felt-likematerial) and a film of polyurethane or an equivalent film of waterimpermeable material laminated on at least one face of the microfiberlayer. The material may be chosen more or less rigid depending on theuse of the boot 10. For example, for street use, the material may beselected to be more flexible than for construction or mining use. Theselection of the rigidity may be made via the selection of the materialor by the selection of thickness of the material. The material and/orthickness of the material may also be chosen to resist to cuts anddents. Depending on the use of the boot 10, the material may be acidresistant, scratch resistant or fire resistant to name a few.

The panels 14 a, 14 b are waterproofly bonded to each other at bond 27.In one embodiment, an adhesive 22 bonds a portion (i.e. rim) of theinternal surface 16 a of the panel 14 a to a portion (i.e. rim) of theexternal surface 15 b of the panel 15 b. In that embodiment, no sewingis needed, the adhesive 22 ensuring bonding and waterproofing of theconnection between the panels 14 a, 14 b. Alternatively, a radiofrequency (RF) bonding process may be used to bond the panels together.

As a result of choosing the panels 14 a, 14 b to be waterproof, andbonding them waterproofly, the external shell 14 has its outer mostsurface 24 waterproof. Waterproofing of the boot 10 is thus achieved atthe outer most surface 24 of the boot 10. As such, water, humidity andvapor coming from the environment may be deflected off the outer mostsurface 24 upon contact with it, as illustrated by arrow 20 in FIG. 1.As a consequence, environment water may not accumulate on the boot 10 orin the boot 10 as it does in leather boots. In the embodiment shown inthe Figures, the external shell 14 also has its inner most surface 23waterproof which deflects water generated in the inside 18 of the boot10 (as illustrated by arrow 21 in FIG. 3). It is however contemplatedthat the inner most surface 23 could be covered with a cloth such asfelt

A rear 25 of the boot 10 may be sewn at seam 29 (shown in phantom inFIG. 1) and covered by a back strap 26. The panel 14 b (or other panelsif the boot 10 is made from more than two panels) may be brought side toside to form the rear 25 of the boot 10. The sides may be sewn to eachother and covered by the back strap 26. The back strap 26 may be made ofa same material as the panels 14 a, 14 b and may be adhesively securedto the panel 14 b as per the various procedures described above. Theback strap 26 covers the seam 24 such that the rear 25 of the boot 10 iswaterproof.

Referring more specifically to FIG. 3, the inside 18 of the boot 10includes the wicking internal layer 13 disposed adjacent to the externalshell 14. The internal layer 13 may be directly connected to the sole 12by, for example, gluing a lower rim of the internal layer 13 to the sole12. The internal layer 13 may be connected to the external shell 14solely at the sole 12 and at a rim 10 e of the boot 10. The internallayer 13 may be sewn to the external shell 14 at the rim 10 e of theboot 10. In other cases, the internal layer 13 may be sewn to theexternal shell 14 at discrete points on the boot 10.

Unlike the external shell 14, the internal layer 13 is not waterproof.The internal layer 13 is made of a material capable of absorbinghumidity that may arise from the feet of the wearer at the foot portion10 a of the boot 10. The internal layer 13 may also wick or transportthe humidity or water formed at the foot portion 10 a toward the calfportion 10 b of the boot 10. The internal layer 13 may not be attachedto the inner most surface 23 of the external shell 14 such that a gap 32of air is be formed between the external shell 14 and the internal layer13. The gap 32 allows the internal layer 13 to dry faster than it wouldif glued to the external shell 14.

In one embodiment, the internal layer 13 is made of woven or non-wovenfabric backed with a light foam. For instance, a material commercializedunder the trade mark Cambrelle® could be used. The internal layer 13 maybe backed or not with wicking foam. The foam may also be chosen toprovide added comfort to the wearer. The internal layer 13 may be madeof two or more layers of material, some may have wicking properties, andsome may not. The internal layer 13 may be unitary made or made ofpanels sewn to each other. The internal layer 13 may be made of amaterial that is soft at the contact with the skin. The internal layer13 may be formed of a single material or from a plurality of materials.For example, a first material may be used towards the foot portion 10 aof the boot 10 and another material may be used toward the calf portion10 b of the boot 10.

As shown in dotted line in FIG. 1, the boot 10 may further include oneor more reinforcing pieces 33 disposed between the external shell 14 andthe internal layer 13. The reinforcing piece 33 may, for example, be atoe cap disposed at a toe portion 10 c of the boot 10 to protect the toeof the user from being damaged by a heavy object. The reinforcing pieces33 may also include a heel support disposed at a heel portion 10 d ofthe boot 10 to provide support to the foot of the user. The reinforcingpieces 33 could be made, for example, of metal, plastic, fiber glass,leather, or thermoplastic depending on the application of the boot 10.The reinforcing pieces 33 may be disposed between the external shell 14and the internal layer 13 during assembly of the boot 10, as will bedescribed below, or may be connected, such as glued, to one of theexternal shell 14 and the internal layer 13.

As shown in FIG. 1 a, the boot 10 may further include one or more pads33 a disposed between the external shell 14 and the internal layer 13.The pads 33 a may be used to provide added comfort and foot support. Thepads 33 a may be made of foam and may be glued to the inner most surface23 of the external layer 14.

Turning now to FIGS. 4 to 6, the boot 10 may be provided with dryinginserts 34 a and 34 b to further enhance the drying capabilities of theboot 10. The drying inserts 34 a, 34 b may be located at the calfportion 10 b of the boot 10 away from the sole 12 and the foot portion10 a in order to avoid contact with water coming from the environment.According to some applications (e.g. golf shoes) the drying insert couldbe disposed close to the sole 12.

The drying inserts 34 a, 34 b may be provided in the form of breathablemembranes or fabrics impermeable to liquids but permeable to watervapor.

FIG. 4 shows a first embodiment of the drying insert 34 a. The dryinginsert 34 a is disposed in an aperture 36 or window defined in theexternal shell 14. The window may be defined in one of the panels with adie prior to assembling the external shell of the boot. The dryinginsert 34 a may be bonded to the inner surface of the external shell soas to cover the aperture 36. The aperture 36 allows direct contact ofthe drying insert 34 a with the outside 18 of the boot 10 (i.e.environment). The water vapor conveyed by the wicking liner 13 can bevented to the atmosphere through the drying inserts. The water vaporflows from the wicking liner 13 to the drying inserts 34 a by diffusion.

FIG. 5 shows a second embodiment of the drying insert 34 b. The dryinginsert 34 b is similar to the drying insert 34 a except that it isdisposed in front of a cut-out 37 of the external shell 14.

FIG. 6 shows a third embodiment wherein a collar 34 c of the internallayer 13 is exposed to the outside of the external shell, therebyallowing humidity to be exhausted away from the wearer's foot directlyvia the wicking internal layer 13. The collar may be bonded to a rim 38of the external shell 14. The collar 34 c may include a string 39 totighten it around a calf of the user.

Turning now to FIG. 7, a method 50 of manufacturing of the boot 10 willbe described.

The method 50 starts at step 52 with the formation of the external shell14. The formation of the external shell 14 starts with cutting of thepanels 14 a, 14 b in the waterproof material described above, andselecting the material in a manner described above. The cutting of thepanels 14 a, 14 b may also include the formation of the window 36 or thecut-out 37. The drying insert 34 a, 34 b, 34 c are positioned over thewindows and bonded to the inner surface of the panels. The shape andsize of the panels 14 a, 14 b may be dictated by a predefined pattern.Once the panels 14 a, 14 b are cut, they are waterproofly bonded to eachother at the bond 27. As mentioned above, a suitable glue can be used toglue a portion (i.e. rim) of the panel 14 a onto a portion (i.e. rim) ofthe panel 14 b, such that the panels 14 a, 14 b have only a smalloverlapping portion. Pressure may be mechanically locally applied ontothe bonding to solidify it in order to ensure waterproofness. Thebonding described above results not only in a waterproof shell but alsoin an aesthetically pleasing boot, where the bond 27 provides a seamlesseffect.

Before the panels 14 a, 14 b are brought together to form the externalshell 14, the pads 32 may optionally be glued to the inner most surface23 of the external shell 14 according to a predefined pattern definingpositions of the pads 32.

Once the panels 14 a, 14 b are bonded to each other, sides of the panel14 b are brought in a side-by-side relationship to form the seam 24. Aboot last may be used to facilitate this operation. It is contemplatedthat the seam 24 could be made before the panel 14 a is bonded to thepanel 14 b. The sides of the panels 14 b are sewn to each other andthereafter the back strap 26 is waterproofly bonded to over the seam 24in a manner described above. At the end of the above steps, the externalshell 14 is formed. The external shell 14 at that stage has a generaltubular shape.

From step 52, the method 50 goes to step 54, where the internal layer 13is formed. It is contemplated that the internal layer 13 could be donebefore or at the same time as the external shell 14. The internal layer13 is formed by sewing one or more pieces of the wicking materialdescribed above. The pieces to be sewn may be determined using apredefined pattern. If required by the predefined pattern, pads such asthe pads 32 may optionally be sewn to a surface of the internal layer 13which is to be facing the inner most surface 23 of the external shell14. Once the internal layer 13 is formed, it has a general tubularshape. The internal layer 13 is then slid inside the external shell 14and sewn to the rim 38 of the external shell 14.

The assembly formed by the internal layer 13 and the external shell 14may be placed on the boot last. The reinforcing pieces 33 may be placedbetween the internal layer 13 and the external shell 14. Some may besecured by an adhesive or sewn to the external shell 14, other may justbe placed between the internal layer 13 and the external shell 14.

From step 54, the method 50 goes to step 56, where the sole 12 iswaterproofly glued to lower rims of the internal layer 13 and theexternal shell 14 so as to close the boot 10.

The above boot and method provide a light boot that is waterproof inboth directions, and which at the same time allows an inside of the bootto dry relatively fast. The construction of the boot requires few stepsand allows to manufacture the boot in a small amount of time. Theconstruction of the boot also employs steps that are common totraditional boot manufacturing which allows to build this boot withoutmajor investment in new machinery and production methods. The boot mayprovide a compromise between leather boot which are breathable yet notwaterproof and rubber boots which are waterproof but not breathable. Theboot may be adapted to various environments ranging from city tooutdoors and heavy duty. Because the waterproofing is obtained by theexternal shell and not by the internal layer, the addition of dryinginserts is relatively easy. The multiply panel construction of thepanels used to form the external shell allows to preserve theimpermeability of the external shell even in the event of puncturing orripping of the outermost layer of the shell.

The above description is meant to be exemplary only, and one skilled inthe art will recognize that changes may be made to the embodimentsdescribed without departing from the scope of the invention disclosed.Other modifications which fall within the scope of the present inventionwill be apparent to those skilled in the art, in light of a review ofthis disclosure, and such modifications are intended to fall within theappended claims.

1. A waterproof breathable boot comprising: a sole; an external shellextending and connected to the sole, the external shell having an outermost waterproof surface, the external shell including at least twopanels having an outer surface and an inner surface, each panel havingan outer surface and an inner surface, the outer surface of the at leasttwo panels forming part of the outer most waterproof surface of theexternal shell, the outer surface and the inner surface of each panelbeing waterproof, the at least two panels being waterproofly bonded toeach other, the waterproof bonding including an overlapping of a firstportion of the inner surface of one of the at least two panels with asecond portion of the outer surface of the other one of the at least twopanels; an internal layer separate from the external shell and connectedto the external shell by the sole such that a gap of air is formedbetween the internal layer and the external shell, the internal layerhaving wicking properties, the internal layer being protected from anoutside of the boot by the external shell; and at least one dryinginsert integrated to the external shell, the internal layer carryinghumidity from the wearer's foot to the at least one drying insert. 2.The waterproof breathable boot as defined in claim 1, wherein theexternal shell includes at least one layer of polyurethane.
 3. Thewaterproof breathable boot as defined in claim 1, wherein the internallayer has a collar extending outwardly from an upper end of the externalshell.
 4. The waterproof breathable boot as defined in claim 1, whereinthe at least one drying insert is mounted in a window defined in theexternal shell.
 5. The waterproof breathable boot as defined in claim 1,further comprising a rear seam between the at least two panels, the rearseam extending upwardly from a heel portion of the external shell, therear seam being covered by a back strap, the back strap being made ofimpermeable material and forming part of the external shell, an adhesivebeing in direct contact with the back strap and portions of the at leasttwo panels covered by the back strap.
 6. The waterproof breathable bootas defined in claim 1, wherein the at least one drying insert is made ofa membrane or fabric impermeable to liquid but permeable to water vapor.7. The waterproof breathable boot as defined in claim 1, wherein theexternal shell has an innermost surface, said innermost surface beingimpermeable, thereby providing for an external shell which isimpermeable on both the inside and the outside.
 8. The waterproofbreathable boot as defined in claim 1, wherein a vamp of the boot ismade of a single piece of one of the at least two panels.
 9. Thewaterproof breathable boot as defined in claim 1, wherein the waterproofbonding further comprises an adhesive in direct contact with the firstportion of the inner surface and the second portion of the outer surfacefor waterproofly bonding the first portion to the second portion.
 10. Amethod of manufacturing a waterproof breathable boot, the methodcomprising: cutting at least two panels in a waterproof material havingan outermost waterproof surface, the panels being cut in accordance to apattern of the waterproof breathable boot; positioning at least one ofthe two panels onto a foot last and sewing adjacent sides of the panelsforming a back of the boot so as to create a back seam; waterprooflybonding a back strap onto the back seam, the back strap beingwaterproof; waterproofly bonding a portion of an inside of at least oneother panel to a portion of an outside of the at least one of the twopanels so as to form a vamp of the boot until forming a waterproofexternal shell, an outer most surface of the external shell beingwaterproof; forming a wicking internal layer and disposing it inside theexternal shell; and securing the wicking internal layer and the externalshell to a sole.
 11. The method as defined in claim 10, furthercomprising locally applying pressure to the waterproof bonds.
 12. Themethod as defined in claim 10, wherein forming the wicking internallayer comprises cutting portions of a wicking material and sewing themaccording to a pattern of the boot.
 13. The method as defined in claim10, further comprising mounting a drying insert in a window defined inthe external shell.
 14. The method as defined in claim 10, furthercomprising placing reinforcing pieces between the external shell and theinternal layer.
 15. The method as defined in claim 10, furthercomprising placing pads between the external shell and the internallayer and connecting the pads to at least one of external shell and theinternal layer.
 16. The method defined in claim 10, wherein thewaterproof bonding is done using an adhesive.
 17. A waterproofbreathable boot comprising: a sole; an external shell extending upwardlyfrom the sole, the external shell having an outer most waterproofsurface, the external shell including at least two panels having anouter surface and an inner surface, each panel having a multiplyconstruction including at least one impermeable film laminated on amicrofiber substrate, the impermeable film being provided at said outersurface of said at least two panels to form part of the outermostwaterproof surface of the external shell, the at least two panels beingwaterproofly bonded to each other, the waterproof bonding including anoverlapping of a first portion of the inner surface of one of the atleast two panels with a second portion of the outer surface of the otherone of the at least two panels; and an internal layer mounted in theexternal shell with a gap of air therebetween, the internal layer havingwicking properties for carrying humidity away from the wearer's foot.18. The boot defined in claim 17, wherein at least one drying insert ismounted in a window defined in the external shell at a location spacedfrom the sole, the internal layer carrying humidity from an areaproximal to the sole to the at least one drying insert.
 19. The bootdefined in claim 17 wherein the microfiber substrate is laminated onboth sides thereof with said impermeable film thereby providing at leasttwo impermeable layers across a thickness of the external shell, a firstone of the impermeable layer being provided at said outer most surfaceof the external shell and a second one of the impermeable layer beingprovided at an innermost surface of the external shell.